1. Field of the Invention
This invention concerns a packaging tape and, more specifically, it relates to a packaging tape having a self-adhesive layer at least on one surface thereof for use in sealing, bundling of packaging articles.
2. Description of the Prior Art
Sealing or bundling of articles has often been carried out using plastic films or tapes, for instance, made of polyethylene and polyvinyl chloride, or fiberous or paper-made strings by winding them tightly around the articles and then securing or binding the final end of them. Since the tightening effect for an article is exclusively obtained by the frictional contact between the surface of the article and the films or the strings, for obtaining reliable packaging or bundling with no slacks, it requires somewhat complicated and skilled labours of continuously applying a uniform tension to the film or string during the winding work and then fastening the winding end by means of tape seizing or string not under the tension.
Use of so-called pressure-sensitive adhesive tapes for such applications can significantly save the labours due to the strong adhesive performance of the adhesive tapes to the surface of the articles.
However, intense bond strength of the adhesive tapes to the adherents are not always desirable depending on the kinds of articles and the purpose of the packaging or bundling. For instance, in a case where paper documents, corrugated boxes or the likes are temporarily bundled or sealed with the adhesive tapes, it is not easy to release the tapes from the surface of the articles once after they have been firmly sticked thereto. Further, if the tapes are released forcively, indications such as printed characters or pictures applied on the surface of the articles or even a part of the article surface per se may sometime be peeled off being sticked to the tapes. Furthermore, dusts or the like are liable to be adsorbed to the residual adhesives transferred from the tapes and remained on the surface of the articles after the release of the tapes, to contaminate the surface and impair the appearance of the articles. The above drawbacks can be overcome to some extent by modifying the composition of the adhesive layer so as to weaken the bond strength of the tape. However, this sacrifices the desired adhesion performance of the tape and, accordingly, can not be used in general packaging applications.